To use novel high-speed fMRI methods to (a) obtain clues about the neural substrates of specific cognitive changes in aging and AD, (b) document individual differences in those changes, and (c) identify neurophysiological markers that may signal very early AD. In order to achieve these goals, we shall perform 60 fMRI studies per year over a 5-year period in subjects with AD, older control subjects, and young control subjects. We shall examine correlations between MRI signal and behavior in three cognitive domains that are vulnerable to the effects of aging and AD: long-term explicit memory, visual perception, and motor control.